{"uid":"cap_HOg36yw4-K8l9tqjvoosl","slug":"agent402-isbn-check-digit-validator-21163fd3","name":"Agent402 ISBN Check Digit Validator","description":"Don't burn tokens on deterministic work. Go/no-go jobs first: payout preflight, text firewall (PII/secrets), budget check — then rails, calendars, finmath. x402 USDC on Base. UK + global. agent402.co.uk — not agent402.tools. $0.001–$0.002 USDC on Base. No API keys.","url":"https://agent402.co.uk/v1/validate/isbn","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"isbn":{"type":"string","description":"ISBN-10 or ISBN-13 (hyphens ok)"}}},"responseSchema":{"type":"json","example":{"kind":"ISBN-13","valid":true,"valid_checksum":true,"bookland_prefix":true}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"down","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_YCGRu1HG_a2EVGCKSfRLg","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates the check digit of an ISBN-10 or ISBN-13 number per ISO 2108, returning validity, kind, and bookland prefix status","exampleAgentPrompt":"Can you check whether the ISBN 978-3-16-148410-0 is valid — specifically confirm the check digit is correct and whether it's an ISBN-13?","exampleUseCases":[{"title":"Pre-ingest catalog ISBN check","prompt":"Before I add this book to the catalog, verify that the ISBN 0-306-40615-2 has a valid check digit so I don't store a corrupt entry."},{"title":"User-submitted ISBN form validation","prompt":"A user just typed in ISBN 9780140328721 on our order form — can you confirm the check digit is correct before we let them proceed to checkout?"},{"title":"Bulk data cleanup flagging","prompt":"I have a record with ISBN 978-0-7432-7356-5 that might have a typo — can you validate the checksum and tell me if it's a proper ISBN-13?"}],"resultDescription":"Returns a JSON object indicating: 'kind' (ISBN-10 or ISBN-13), 'valid' (overall validity boolean), 'valid_checksum' (whether the check digit is correct per ISO 2108), and 'bookland_prefix' (whether the EAN bookland prefix is present, for ISBN-13).","failureModes":["Malformed or non-ISBN string returns invalid result or error","Passing a registry lookup query — this endpoint only checks structure/checksum, not whether the ISBN is registered","Providing an empty string may return a validation error","Non-string or missing 'isbn' field in request body causes a schema error"],"whenToPreferThis":"Use this endpoint when you need a fast, cheap, authoritative ISO 2108 check-digit computation for ISBN-10 or ISBN-13 numbers — for example before catalog ingestion, form validation, or data cleaning. It is not a registry lookup (it won't tell you if the book exists or who published it), so prefer it purely for structural/checksum validation at $0.001 per call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T13:25:46.715Z","isFirstParty":false}